Gave up on the Keter thing. Went back to Euclid. Got this idea for a living figure of wood and vegetation attacking and doing who knows what to people who enter its forest. Wanted to run the draft through here.

The general forest area has been fenced off under the pretense of chemical contamination…

"General forest area"

SCP-XXXX is a humanoid figure occupying a general forest area of 8 by 11 kilometers in upper █████████.

Maybe mention this in the containment procedures? And your blackbox isn't specific enough. Stay with me here. You only give one "word"s worth. I don't have any idea what country this is, nevermind the continent. Do you understand me?

It's appears to be between 200 to 215 centimeters in height….

AAAAAAGGGHHHHH
AAAAAAAAAA
NOOOOOOO
I hate the word "appear". Any other word would be better. "The height of SCP-XXXX is estimated to be approximately 207 centimetres in height, based off of initial observations." Or something. Anything. Please. No "appear"s.

Oh, right. "It's" is not correct.

The entity itself is vaguely human in shape, but composed of general wood and vegetation native to the area.

So it's an Ent?

After a rash of hiker disappearances emerged from a specific wooded area, Foundation personnel were sent to ascertain the situation.

I don't think that the Foundation would investigate a series of what are ostensibly murders/kidnappings. Most people don't, I would imagine.

SCP-XXXX was first encountered when █ D-Class personnel were sent in to locate the entity. Only a single D-Class exited the forest. Describing "The wooden man wouldn't quit chasing me!" SCP-XXXX itself emerged soon after this. Demanding the D-Class be handed over to it.

This is just… Well.

The two penultimate paragraphs

They're very fragmented and cliche. Your skip went into a rage state. That's never appreciated.

SCP-XXXX appears aware of Foundation monitoring, frequently appearing to observe the cameras and outposts through the fence. It has yet to attempt hostile actions unless its forest is entered.

Meh.

Final Opinion

This is an Ent. And that's it. Think back to your first SCP, "Lovely Lucy". The people who upvoted it, upvoted it for the story. The emotional resonance it had. As it stands, this has none of that. Remember, we're a creative writing site. The classes, formatting, universe, those are all a means to an end; the story.

Tonal issues again. Reiterate it to "The Foundations attention", the proper form for this sentence.

to Foundation attention in the late

The sentence is constructed wrong and you imply that the Foundation knew what it was before the actually knew what it was.

SCP-XXXX was first encountered when █ D-Class personnel were sent in to locate the entity.

To continue with the above, it should be "Discovered by Class D's when…" The rest doesn't need to be there by way of the first statement.

It's kills for the sake of kills

Only a single D-Class exited the forest.

It wants to kill. We have many other SCP's that do the same thing too. This seriously takes away all remaining appeal.

Demanding the D-Class be handed over to it.

The Class-D's are not children. They are death row inmates.

The wooden man wouldn't quit chasing me!

More gore for gore. If that wasn't enough, it just seems like this is trying to emulate 682.

When the guards on location refused, SCP-XXXX became enraged and attacked the group. 2 guards were killed and the D-Class(D-7449) was obtained by SCP-XXXX and taken into the forest.

So now it's considered dangerous? I would consider the placement of this sentence is dangerous.

SCP-XXXX was determined to be a threat

Why didn't we check things out when it never came!? How do we KNOW that it doesn't move unless disturbed? WHY would a fence work if armed guards didn't?

Erecting a fence around the forest and monitoring it around the clock.

Where are the logs to confirm this?

SCP-XXXX appears aware of Foundation monitoring, frequently appearing to observe the cameras and outposts through the fence. It has yet to attempt hostile actions unless its forest is entered.

So whats wrong here?

First and foremost, it's your generic monster.
2: it's predictable.
Reason Third, Too much gore for gore.
The fourth reason is the most painful. There is a complete disregard for critical information.

Where is are the logs that prove it only moves when you enter the area? Where are the tests? Where is the researcher's spooky endnote that tells us he feels like he's being watched? What backs your claims up?

Then there all all the tonal issues!

End Synapsis

There are a lot of holes that need to be filled before it is "complete". Even then, it will not be good enough for whichever reason. Judging from your previous work, you are a better writer then this. Honestly, you didn't need us to tell you that this was bad. It is obvious. I want to read that good "go with the flow" emotional writing you have in Lovely Lucy. This right here, it's half assed.
And I am serious here. This reads like you put eighth the time and effort that you had in Lovely Lucy and put it in here. Don't do that to yourself.